Security Error when trying to load content from resource in a Firefox Addon (SDK)

Question

I am creating a firefox addon using the SDK. My goal is simple, to intercept a specific iframe and load my own HTML page (packaged as a resource with my addon) instead of the content that was requested originally.

So far I have the following code:

var httpRequestObserver = 
{
    observe: function(subject, topic, data)
    {
        var httpChannel, requestURL;

        if (topic == "http-on-modify-request") {
            httpChannel = subject.QueryInterface(Ci.nsIHttpChannel);
            requestURL = httpChannel.URI.spec;

            var newRequestURL, i;

            if (/someurl/.test(requestURL)) {
                var ioService = Cc["@mozilla.org/network/io-service;1"].getService(Ci.nsIIOService);

                httpChannel.redirectTo(ioService.newURI(self.data.url('pages/test.html'), undefined, undefined));
            }

            return;
        }
    }
};

var observerService = Cc["@mozilla.org/observer-service;1"].getService(Ci.nsIObserverService);
observerService.addObserver(httpRequestObserver, "http-on-modify-request", false);

This code works in that it detects the proper iframe loading and does the redirect correctly. However, I get the following error:

Security Error: Content at http://url.com may not load or link to jar:file:///.../pages/test.html.

How can I get around this limitation?

Answer 1

posting my trials here so it can help all:

trail 1 failed - created chrome.manifest file with contents content kaboom-data resources/kaboom/data/ contentaccessible=yes

var myuri = Services.io.newURI('chrome://kaboom-data/content/pages/test.html', undefined, undefined);
httpChannel.redirectTo(myuri);

Error Thrown

Security Error: Content at http://digg.com/tools/diggthis/confirm? may not load or link to jar:file:///C:/Documents%20and%20Settings/SONY%20VAIO/Application%20Data/Mozilla/Firefox/Profiles/vr10qb8s.default/extensions/[email protected]!/resources/kaboom/data/pages/test.html.

trial 2 failed - created resource in bootstrap.js

alias.spec = file:///C:/Documents%20and%20Settings/SONY%20VAIO/Application%20Data/Mozilla/Firefox/Profiles/vr10qb8s.default/extensions/[email protected]

alias updated to spec: jar:file:///C:/Documents%20and%20Settings/SONY%20VAIO/Application%20Data/Mozilla/Firefox/Profiles/vr10qb8s.default/extensions/[email protected]!/

   let resource = Services.io.getProtocolHandler("resource").QueryInterface(Ci.nsIResProtocolHandler);
  let alias = Services.io.newFileURI(data.installPath);
  Cu.reportError('alias.spec = ' + alias.spec);
  if (!data.installPath.isDirectory()) {
    alias = Services.io.newURI("jar:" + alias.spec + "!/", null, null);
    Cu.reportError('alias updated to spec: ' + alias.spec);
  }
  resource.setSubstitution("kaboom_data", alias);

...

var myuri = Services.io.newURI('resource://kaboom_data/resources/kaboom/data/pages/test.html', undefined, undefined);
httpChannel.redirectTo(myuri);

Error Thrown

Security Error: Content at http://digg.com/tools/diggthis/confirm? may not load or link to jar:file:///C:/Documents%20and%20Settings/SONY%20VAIO/Application%20Data/Mozilla/Firefox/Profiles/vr10qb8s.default/extensions/[email protected]!/resources/kaboom/data/pages/test.html.

CONCLUSION in both trials above it was the weirdest thing, it wouldnt show the resource or chrome path in the security error thrown but it would give the full jar path. Leading me to believe that this has something to do with redirectTo function.

The solution that did work was your solution of

var gBrowser = utils.getMostRecentBrowserWindow().gBrowser;
var domWin = httpChannel.notificationCallbacks.getInterface(Ci.nsIDOMWindow);
var browser = gBrowser.getBrowserForDocument(domWin.document);

//redirect
browser.loadURI(self.data.url('pages/test.html'));

however I changed this to use loadContext instead of this method because it is the recommended way. also gBrowser to getMostRecentBrowserWindow will fail if the url load is slow and in that time the user swithces to another tab or window

I also changed to use Services.jsm as you had imported Cu anyways. Using Services.jsm is super fast not even blink fast. Its just a pointer.

Im still working on trying to the redirectTo method working its really bothering me. The changes I made are to my local copy.

Answer 2

Have you considered turning your local HTML file into a data URL and loading that?